Intake of a Jet Engine

Description

This project investigates three-dimensional airflow within a cylindrical jet intake geometry using ANSYS Fluent, examining how intake design influences flow acceleration, pressure variation, and mass flow distribution — factors critical to aircraft engine inlet performance across various flight conditions.

Methodology

The three-dimensional geometry, featuring a variable cross-sectional area for flow conditioning, is built in ANSYS Design Modeler and meshed in ANSYS Meshing with 389,136 cells to capture flow transitions and boundary layer behavior accurately. The simulation runs as a steady-state case with the standard k-epsilon turbulence model, chosen for reliable prediction of confined internal flow. Air enters at a velocity inlet of 3.55 m/s, with a pressure outlet and no-slip wall conditions applied to the intake walls.

Analysis

The results show flow acceleration from an inlet velocity of 3.55 m/s to a maximum internal velocity of 3.6 m/s, driven by the reduction in cross-sectional area, along with a corresponding pressure rise to a maximum upstream value of 5.96 Pa as the flow is conditioned through the intake. The calculated mass flow rate of 0.02525548 kg/s confirms consistent flow delivery through the intake geometry. Streamline and velocity field visualization reveal flow acceleration zones and identify any regions of flow separation, while the pressure field highlights stagnation regions and recovery mechanisms along the flow path — together providing insight relevant to subsonic intake design, with implications extending to supersonic and engine integration considerations where intake performance directly affects overall propulsion system behavior.